Cuauhtémoc Francisco Pineda Muñoz

El lactosuero dulce, es un subproducto de la industria quesera, que constituye un vertido de elevada carga orgánica (DQO: 50,000-55,000 mg O2/L; DBO: 30-50 g/L) excediendo ampliamente los límites de descarga establecidos por la normativa ambiental mexicana. En el Valle de Tulancingo, Hidalgo, se estima que se generan diariamente alrededor de 80,000 L diarios de este efluente que se vierte sin tratamiento sobre suelos y cuerpos de agua, provocando eutrofización y disminución del oxígeno disuelto en los ecosistemas acuáticos receptores. Este trabajo evalúa la fermentación de lactosuero crudo con la levadura Kluyveromyces marxianus como estrategia de tratamiento biotecnológico optimizada mediante Metodología de Superficie de Respuesta (MSR) con un Diseño Compuesto Central. Bajo condiciones óptimas (4.50 g/L de L-fenilalanina, 0.76 g/L de (NH4)2SO4, 28°C, pH 4.8), se alcanzó una remoción de DQO de hasta un 76% en 96 horas y una remoción de lactosa del 99.4%, transformando un efluente no apto para descarga, en un residuo ambientalmente manejable. El proceso genera simultáneamente 2-feniletanol (1.1 g/L), bioetanol (hasta 25.13 g/L) y acetato de isoamilo (0.923 g/L), subproductos de valor comercial que contribuyen a financiar el costo del tratamiento sin comprometer su función ambiental primaria. Los resultados demuestran que la fermentación con K. marxianus constituye una alternativa de tratamiento de bajo costo y alto co-beneficio para efluentes lácteos de elevada carga orgánica, con potencial de escalamiento en otras regiones queseras del país.

The purpose of this article was to describe some of the effects of climate change on the coffee agroforestry, from a global perspective to the impacts on coffee growers in the state of Guerrero, Mexico. It is hoped that this article will help coffee producers, technicians, and local authorities understand the different strategies, utilizing agroecology and biotechnology, to strengthen the resilience of the coffee agroforestry in Guerrero to climate change. The article was developed through a documentary review and comparative analysis of scientific, technical, and community sources. The vulnerability of coffee to climate variability was examined, identifying temperature increases, irregular rainfall, and emerging pests that affect its productivity and sustainability. The argumentative development integrated agroecological practices such as shade diversification, biofertilization, and soil conservation with biotechnological tools such as the use of bioinputs, biological control, and genetic improvement, highlighting their complementarity. It was concluded that the synergy between agroecology and biotechnology represents a viable path to building a sustainable coffee model based on science and peasant knowledge. This integration promotes ecological resilience, food security, and social justice, positioning Guerrero as a national leader in rural innovation.

In many countries, whey from the dairy industry is an abundant waste that generates an important environmental impact. Alternative processes to use the whey and minimize the environmental impact are needed. This work considered six formulations with different ammonium sulfate and L-phenylalanine (L-Phe) concentrations to produce bioethanol in sweet whey fermentation by Kluyveromyces marxianus. The results showed a maximum bioethanol concentration equal to 25.13 ± 0.37 g L⁻¹ (p < 0.05) for formulation F6, with 1 g L⁻¹ of L-Phe and 1.350 g L⁻¹ of ammonium sulfate (96 h). For these conditions, the chemical oxygen demand removal percentage (CODR%) was 67%. The maximum CODR% obtained was 97.5% for formulation F3 (1 g L⁻¹ of L-Phe) at 96 h; however, a significant decrease in bioethanol concentration (14.33 ± 2.58 g L⁻¹) was observed. On the other hand, for formulation, F3, at 48 h of fermentation time, a bioethanol concentration of 23.71 ± 1.26 g L⁻¹ was observed, with 76.5% CODR%. Based on these results, we suggest that the best conditions to obtain a significant bioethanol concentration and CODR% value are those used on the configuration F3 at 48 h.

In some fermentation systems, whey components (lactose, proteins and minerals) can produce isopentyl acetate (IA). An analysis of the best conditions for IA production with Kluyveromyces marxianus was developed in this work. The experiment design was two-factor and three-level design based on a response surface methodology (RSM) using Design-Expert^® software. The analysis of anomeric protons by nuclear magnetic resonance (1H-NMR) showed 81.25% of β lactose content. This characteristic favored the production of IA. The maximum output (Mp) of IA, determined by gas chromatography, was 9.52 g/L (p < 0.05). The central composite design (CCD) was used to perform the factor analysis. Results showed that concentrations of 0.03 (g/L) ammonium sulphate and 0.3 (v/v) of isoamyl alcohol are the best conditions for a maximum rate of IA production. The production of IA can reduce the discharge of whey, allowing its reuse and revaluation.